Fig. 9.
Inhibition of rat Nav1.4 and Nav1.4/V787K sodium channels expressed in Xenopus ooyctes. (A) Example current traces illustrating the approximately equivalent induction of slow inactivation of both variants. Top: traces recorded from Nav1.4 channels at holding potentials of either −120 mV or −30 mV. Bottom: traces recorded from Nav1.4/V787K channels at holding potentials of −140 mV or −110 mV. Currents from both channels held at depolarized potentials were recorded during 20-ms test pulses to −10 mV that was preceded by a 2-s repolarizing pulse to the holding potential (−120 or −140 mV depending on the variant examined). (B) Fractional inhibition of Nav1.4 and Nav1.4/V787K channels measured using the pulse protocols illustrated in Panel A 15 min after perfusion with SCI insecticides at 10 µM. The figure is re-drawn from the data of von Stein and Soderlund [22].